Effect of jejunal nutrition on pancreatic exocrine secretion in pancreatitis rats and the involvement of the nucleus tractus solitarius

https://doi.org/10.1016/j.autneu.2005.12.007Get rights and content

Abstract

Jejunal nutrition is currently used as a fundamental therapeutic measure for acute pancreatitis. Its impact on pancreatic exocrine secretion (PES) is still on dispute. The aim of this study was to determine the effect of jejunal nutrition on PES and illuminate whether NTS is involved in the regulation of PES. Firstly, we established experimental acute cutaneous pancreatitis (ACP) and acute necrotic pancreatitis (ANP) rat models, and measured the volume and protein levels of pancreatic fluid in normal and pancreatitis rats, and found that pancreatitis rats had a significantly lower pancreatic fluid volume and protein level than the normal rats. Then, we gave 0.3 mol/l maltose and 3% saline as jejunal nutrition were given to the two groups, respectively, and found that the jejunal nutrition did not increase the PES levels in both groups. In addition, we analyzed c-Fos expression in the nucleus tractus solitarius (NTS), and found c-Fos expression in NTS was stronger in rats who were given the jejunal nutrition than in those who were not. These findings suggest that jejunal nutrition excites vagal afferent nerve fibers at pancreatitis rats, and the excitation can be transmitted to medulla oblongata, but do not induce changes in PES. It is likely that the central integration mechanism, pathway of vagal efferent nerve or status of effector in acute pancratitis may be different from normal physiological conditions.

Introduction

Acute pancreatitis is a hypermetabolic disease process that creates a catabolic stress status and promotes a systemic inflammatory response and nutritional deterioration. Previous studies have shown that resting energy expenditure is variable in patients with pancreatitis (77% to 139% of predicted energy expenditure) (Dickerson et al., 1991). Nutrition support plays an important role in the adjunctive management of these patients. Meta-analysis shows that in patients with acute pancreatitis, total parenteral nutrition, as compared with enteral nutrition, significantly increases the risk of infective complications, the likelihood of a surgical intervention (to control pancreatic infection) and the length of hospital stay (Marik and Zaloga, 2004). The enteral nutrition avoids the detrimental effects of total parenteral nutrition and thus becomes the more favored nutrition.

The effect of enteral nutrition on pancreatic exocrine secretion (PES) varies depending on where in the gastrointestinal tract the nutrition is infused. Previous studies evaluating the safety and effectiveness of enteral nutrition in pancreatitis have been limited to a few case series. The concern that jejunal nutrition might stimulate PES and have a detrimental effect on clinical outcome necessitates a careful study on the effect of jejunal nutrition on PES (Duerksen et al., 2002). In addition, our previous study revealed that the glutamate receptors within the nucleus tractus solitarius (NTS) contributed to pancreatic secretion stimulated by intraduodenal hypertonic saline in normal rats (Liao et al., 2005). Therefore, the aim of this study was to determine the effect of jejunal nutrition on PES and illuminate whether NTS is involved in the regulation of PES.

Section snippets

General methods

Seventy male 8-week old Sprague–Dawley rats weighting about 250–350 g were used (purchased from Shanghai Slaccas Experimental Material, China). These rats were housed separately in standard house cages in a room with controlled temperature (23 °C) and humidity (60%) and a 12-h light / dark cycle (light on from 6:00 A.M. to 6:00 P.M.), and were given tap water and laboratory chow (Shanghai Slaccas Experimental Material, China) ad libitum.

The animal experiments in the present study were conducted

Biochemical and histological changes in acute pancreatitis

Four intraperitoneal injections of cerulein induced acute pancreatitis in rats, with marked hyperamylasemia, pancreatic edema, and morphologic changes (Table 1, Fig. 2).

Basal PES of rats in normal, ACP and ANP models

The basal pancreatic fluid secretion 12 h after the first cerulein injection was significantly decreased (0.42 ± 0.30 vs. 0.35 ± 0.32 ml/15 min in ACP rats, P < 0.01) and (0.42 ± 0.30 vs. 0.27 ± 0.54 ml/15 min) in ANP rats. The protein level was decreased in ANP rats (446.69 ± 116.5 vs. 342.32 ± 87.87 μg/ml, P < 0.01), but not in ACP rats.

Discussion

Although drugs and procedures inhibiting pancreatic secretion have been used in the treatment of acute pancreatitis for many years, all previous attempts have been unsuccessful. Furthermore, there are only a few reports concerning pancreatic secretory function in patients with acute pancreatitis, in particular during the early phase of the disease. In experimental studies, it is shown that pancreatic enzyme secretion is reduced after the induction of acute pancreatitis. A dramatic reduction in

Acknowledgments

This work was supported by grant from the National Natural Science Foundation of China (No. 30370647).

References (17)

There are more references available in the full text version of this article.

Cited by (0)

View full text
Copyright © 2005 Elsevier B.V. All rights reserved.